As part of the "NIH/DC Initiative to Reduce Infant Mortality" a program of research aimed at increasing the proportion of infants and children in the District of Columbia who are age-appropriately immunized has been developed. The purpose of this study is to identify psychological, sociological and other factors associated with low rates of immunization and low rates of well-child care. Factors found to be associated with these outcome can then serve as targets for future interventions by public health and medical officials and policy makers. Mothers enrolled in the study are interviewed shortly after giving birth. This "baseline" interview includes information on sociodemographic characteristics of the mother, father and infant; the mother's medical history; psychosocial features of the family; and maternal knowledge, beliefs and practices surrounding well- child care and immunizations. Two "follow-up" interviews are conducted, one when the infant is between 3-7 months of age and one when the infant is between 7 months and one year of age. A number of questions and topics covered on the baseline interview (e.g. perceived social norms regarding immunization practices) are repeated in the three-and-seven month interviews. Additionally, outcome data on health care visits and immunizations are collected during these "follow-up" interviews. Information obtained in the three-and seven-month interviews on immunizations and health care visits is verified via inspection of medical records at the identified provider sites. Investigators on this project include epidemiologists, behavioral scientists, health care providers and administrators. The program of research was developed with input from the variety of perspectives represented by the investigators, and the proposed studies have the potential to benefit from a unique blend of epidemiology, behavioral science, and public health and health care practice.